@ nukemaster
Since your post is poorly formatted and sort of annoying to read I'll just address the most important stuff.
1) it doesn't pause downloads when I'm using a non steam game, nor when other people using the connection are playing games (it can't know that).
2) Okay so it may not be based on firefox, but it requires the firefox version of flash to be installed - and regardles, the other browsers support tabbed browsing too, which is sort of my point.
3) The search isn't good by any stretch. You can't even click to find mods that are free for the games you've installed, or click to only display free games, or apply any other useful filters or a price range. And since you don't have tabbed browsing, you have to click back to page 13 or whatever you were at after clicking on a title to see the details. Nor is there something that allows you to see new releases since you last checked the store. Hell even the release dates listed aren't trustworthy. Some games are listed as from 2008 when they've merely arrived at steam in 2008 but are older. And other games have inaccurate release info. Like one game that I preordered, that sais it'll be released 'november 2010' - we're halfway thru it, and it still isn't released - not even a date is added.
4) by assuming everybody is like you, you limit the use of steam to people like you. Not everybody is like you, and thus not everybody is content with being dictated by valve how things are supposed to work.
#4 is the most important one obviously.